This invention is directed to the damping of shock and vibration through the use of passive shock absorbing and damping devices. Particularly the invention is directed to an enclosure that contains a multitude of small damping particles, wherein restrictions to the free flow of these damping particles are provided by structures within the enclosures.
The enclosures have been filled with a multiplicity of rollable bodies or pellets, such as tungsten carbide to provide for shock absorption and damping. These particles typically have been provided in smoothed wall-hollowed enclosures, either with no other structure within the enclosure, or they have been used in conjunction with pistons where they have react against the movement of the piston. Many different type of materials have been employed and the type of material could be critical for some applications.
Examples of such prior art devices are found in U.S. Pat. No. 3,630,047 issued to Frank Arnold Turton on Dec. 28, 1971 entitled xe2x80x9cCryogenic Cooling Apparatus;xe2x80x9d U.S. Pat. No. 3,938,625 issued to Gunther Radermacher, et. al. on Feb. 17, 1976 entitled xe2x80x9cVibration Damping Device Especially for Protecting Pipelines from Earthquakes;xe2x80x9d U.S. Pat. No. 4,173,130 issued to Wayne N. Sutliff, et. al. on Nov. 6, 1979 entitled xe2x80x9cDrilling Shock Subxe2x80x9d; U.S. Pat. No. 5,027,715 issued to Archie S. Moore, et. al. on Jul. 2, 1991 entitled xe2x80x9cShock Absorbing Carrierxe2x80x9d, and U.S. Pat. No. 5,632,206 issued to Gareth D. Summa, et. al. on May 27, 1997 entitled xe2x80x9cAdjustable Cushion Tow Bar for Power and Free Conveyor.xe2x80x9d
Other Prior Art examples are found in U.S. Pat. No. 1,294,467 issued to John N. Hovas on Feb. 18, 1919 entitled xe2x80x9cShock Absorber;xe2x80x9d U.S. Pat. No. 2,155,052 issued to Conrad Friedrich Byland on Apr. 18, 1939 entitled xe2x80x9cMeans for Destroying the Energy of Mass Oscillations of Solid Bodies;xe2x80x9d U.S. Pat. No. 2,869,700 issued to George W. Bowden on Jan. 20, 1959 entitled xe2x80x9cPositive Clutch with Damping Arrangement;xe2x80x9d U.S. Pat. No. 3,456,782 issued to John D. Miller in Jul. 22, 1969 entitled xe2x80x9cPackage for Elongate Frangible Articles Having Wide Thin Extremity Portions;xe2x80x9d U.S. Pat. No. 3,899,100 issued to Raymond L. Rigaud on Aug. 12, 1975 entitled Container for Packaging an Object;xe2x80x9d U.S. Pat. No. 4,858,738, issued to Fernando Novoa on Aug. 22, 1989 entitled xe2x80x9cSystem of Auxiliary Mass Dampers to Restrain the Response of Slender Elastic Structures to Vibrations such as From Earthquakes;xe2x80x9d U.S. Pat. No. 5,020,644, issued to Fernando Novoa on Jun. 4, 1991, entitled xe2x80x9cAuxiliary Mass Damper for Slender Flexible Element Subject to Vibration;xe2x80x9d U.S. Pat. No. 5,306,100 issued to David D. Higginbotham on Apr. 26, 1994, entitled xe2x80x9cVoid Filler;xe2x80x9d U.S. Pat. No. 5,486,078 issued to Wise et. al on Jan. 23, 1996, entitled xe2x80x9cReusable Void Filler and Construction Method Therefore;xe2x80x9d Document SU-1084504A, published Apr. 7, 1980 in the name of Briskin, et. al., and Document SU-1392277A, dated Apr. 30, 1988 in the name of Oganyan, et. al.
In this type of damping device, collisions of a multitude of particles that are set into motion during the occurrence of a shock, or vibration results and translates energy applied to the device into momentum and heat. These particles generally have a high density and, as they are accelerated, the turbulent motion of the particles results in energy translation from the enclosure wherever the enclosure is engaged by the particles. The particles thus dissipate the energy of the applied force by particle collisions and frictional loses with the walls of the enclosure. Spaced-apart substantially solid disks in a container filled with particulate material to create damping are also shown in U.S. Pat. No. 1,294,467 issued to J. N. Novak and filed Feb. 18, 1919, where they are employed in conjunction with a piston.
Although active damping shock absorber devices have many applications, there are many applications where the cost and complexity of such devices is undesirable. The present invention, by incorporating passive structures of a unique construction and arrangement into the interior of these smooth wall enclosures, provides structure in the interior of the enclosure that restricts the free flow of the damping materials, thereby substantially improving the damping and absorbing characteristics of this type of shock absorbing device.
A device for dissipating mechanical forces is provided by a partially filled, sealed circular cylindrical container partially filled with particulate material. Wheel-like structures with rims and spokes located in the interior of the container which have dimensional variations that substantially increase the flow resistance encountered by said particulate material in the container over the flow resistance encountered by the particulate material without the dimensional variations.
In the disclosed embodiment, a circular cylindrical container with two sealed ends has an elongated central axis, and a plurality of structures are positioned at spaced apart intervals along the elongated axis. Each of said structures is formed by:
a circular rim that has a circular circumference that is proportioned in size to the distance that the structure is positioned along the elongated axis from the centroid of a circular cylindrical container along the elongated central axis toward one of the sealed ends;
a plurality of substantially straight spokes, each of which projects from the rim to join with the other spokes at the center of the rim; and a plurality of support wires that extend between the first sealed end and the second sealed end and are connected so as to support the rims in planes substantially normal to the elongated axis of the circular cylindrical container.